748 ZOOLOGY— INSECTS. 



ally and almost equally toward either extremity, and at first glance much 

 resembles a curled and withered leaf. 



The pupa state is assumed early in July ; the perfect insect escapes 

 the following season. 



A. Ausonides is also found in California, where the specimens are 

 usually larger and the females often have the secondaries suffused with a 

 pale-yellow or creamy tint, rarely seen in Rocky Mountain specimens. 



ANTHOCHARIS CREUSA, Doubleday. 



A. Creusa from Colorado very closely resembles the preceding species ; 

 the difference mainly consisting in the greater amount and darker shade of 

 the green on the lower surface of secondaries. Creusa seems to be confined 

 to the Rocky Mountains. 



ANTHOCHARIS JULIA, Edw. 

 Anthocaris Julia, Edw., Proc. Am. Ent. Soc, 1872. 



This species has only been taken near Fairplay, South Park, Colo., 

 where I found a number of specimens, June 12 to 14, in the woods and on 

 the banks of Beaver Creek. It is the Rocky Mountain representative of 

 the two Californian species Sara and Beakirtii. 



COLIAS, (Fabr.) Leach. 

 COLIAS EURYTHEME, Boise]., and COLIAS KEEWAYDIN, Edw. 

 Colias Eurytheme aud Colias Keewaydin, Edw., Butterflies 1ST. A., i. 



Both species were taken by the expedition. They range from the Mis- 

 sissippi Valley to the Pacific Ocean, and from the level of the sea to 

 upward of ten thousand feet elevation. They are abundant from early 

 spring until frost. Above eleven thousand feet, they are rarely found in 

 Colorado ; in fact, the usual American types are there almost entirely replaced 

 by Arctic species, a considerable proportion of which are common to both 



hemispheres. 



COLIAS POILODICE, Godart. 



This is not so abundant in Colorado as either of the preceding species. 

 Most of the specimens were taken in June. Some of them exactly resemble 

 eastern specimens ; others are paler, and have a somewhat greenish tint on 

 both surfaces. 



